KYOTO, Japan (AP) — In a rare public appearance, respected Japanese writer Haruki Murakami said his latest novel was an experiment and grew longer than expected as he developed a desire to expand on side characters while writing.

“Colorless Tsukuru Tazaki and the Year of His Pilgrimage” has sold more than 1 million copies a week since it went on sale last month.

The novel, whose story was a well-kept mystery up until the book’s release, is about a man healing from a sudden rejection by his friends. Murakami said it reflects his deep interest in real people and relationships rather than allusions.

“At the beginning, I was planning to write something allusive, as in my past works. But this time I developed a great interest in expanding on real people. Then the characters started to act on their own. I was intrigued by the relationships between people,” Murakami said.

The protagonist, Tsukuru Tazaki, a 36-year-old railway station architect, returns to his hometown of Nagoya in central Japan and travels as far as Finland trying to learn why he was rejected 16 years earlier by his best friends — two boys and two girls — in hopes of making a fresh start in life.

In the book, Tazaki’s girlfriend plays a key role in urging him to try to come to terms with his past trauma. Murakami said the girlfriend character, Sara Kimoto, also led him to write more about the four friends.

Murakami said the significance of storytelling is to portray something invisible and deep inside in each person and help create a place where people can sympathize and identify with others.

“If a reader sympathizes with my story, then there is a network of empathy,” he said.

The novel is the first in three years for Murakami and is only available in Japanese for now. Japanese media said his appearance Monday at Kyoto University was Murakami’s first public appearance in Japan in 18 years.

The writer said he could sympathize with Tsukuru’s pain because he had a similar experience, although not as bad.

“I can understand how painful it is to be rejected,” Murakami said. “When you get hurt, you may build an emotional wall around your heart. But after a while you can stand up and move on. . That’s the kind of story I wanted to write.”

Murakami, often mentioned as a Nobel Prize contender, has written such internationally known works as “Norwegian Wood” and “The Wind-Up Bird Chronicle.”

Also an accomplished translator of contemporary American literature, Murakami counts among his influences F. Scott Fitzgerald and Raymond Chandler. Murakami taught as a visiting scholar at Princeton University in the early 1990s.

He is also a prolific nonfiction writer and has published a collection of interviews of survivors and bereaved families of a gas attack on Tokyo’s subways in 1995 by an apocalyptic cult, Aum Shinrikyo.

A vocal opponent of atomic weapons, Murakami has been a critic of Japan’s pro-nuclear energy policies since the 2011 Fukushima disaster.

Murakami’s reclusiveness has added to his appeal.

The last time he appeared in public in Japan was at a book reading after a disastrous 1995 earthquake in Kobe, near where he grew up.

Monday’s event in his birthplace, Kyoto, was tightly controlled. He was interviewed by a veteran literary critic, and no recording or filming was allowed by the media or the audience of 500 who won seats by a lottery.

Murakami, dressed casually in a plaid shirt, brick-colored jeans and navy sneakers, appeared relaxed, but admitted he is media shy.

“When I woke up this morning I almost thought of taking a bullet train home,” he joked. “It’s not because I have a mental condition or purple spots all over my body. I’m just an ordinary person who lives an ordinary life.”

He said his job is to write and he prefers to concentrate on that.

Chiyomi Hirosawa, a 43-year-old architect in the audience, said she was delighted to see Murakami in person.

“It was great to be able to see the real Murakami that we can never know from his novels. He has a great sense of humor and seemed more upbeat than the kind of person I was imagining,” she said.